patchwork: command not found

Have You tried accessing the binary with the full path?

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/bin/patchwork - from package: graphviz

You may install the required package with command apt-get install {package}
Error in other languages:
patchwork: bevel nie gevind nie
patchwork: comandă negăsită
patchwork: comando não encontrado
patchwork: commande introuvable
patchwork: command not found
patchwork: käsku ei ole
patchwork: không tìm thấy lệnh
patchwork: komanda nerasta
patchwork: Kommando nicht gefunden.
patchwork: kommandot finns inte
patchwork: komut yok
patchwork: nie znaleziono polecenia
patchwork: níor aimsíodh an t-ordú
patchwork: no se encontró la orden
patchwork: no s'ha trobat l'ordre
patchwork: opdracht niet gevonden
patchwork: parancs nem található
patchwork: perintah tidak ditemukan
patchwork: príkaz nenájdený
patchwork: příkaz nenalezen
patchwork: команда не найдена
patchwork: командата не е открита
patchwork: 命令找不到
patchwork: コマンドが見つかりません